Has the outcome for extremely low gestational age (ELGA) infants improved following recent advances in neonatal intensive care?

The objectives of this paper are to examine (a) the survival of extremely low-gestational-age (ELGA) infants born at 23-28 weeks' gestational age (GA) and (b) the neurodevelopmental outcome at 18 months corrected age for those born at 23-25 weeks' GA during 1991-1993, when antenatal steroids, surfactant, and dexamethasone for bronchopulmonary dysplasia had become accepted treatments; and to compare with an earlier (1983-1989), previously published large cohort (in a presurfactant era) from our institution. Perinatal and neonatal data on all births delivered at 23-28 weeks' GA at British Columbia's tertiary perinatal center were analyzed for survival rates by GA. Survivors of those born at 23-25 weeks' GA underwent neurodevelopmental assessment at a corrected chronological age of 18 months. The recent cohort (n = 333) of live birth infants, compared to the earlier cohort (n = 911 ) showed a trend toward an overall improved survival to discharge (72 vs. 65%, p = 0.06). Further analysis showed that improved survival was seen only in 26- to 28-week GA infants (86 vs. 76%, p = 0.01), but not in 23- to 25-week GA infants (44 vs. 44%, p = 0.9), even when adjusted for gender or twin births. In addition, the incidence of major impairment at 18 months (36% in both periods) remained high. Reanalysis of 24- to 25-week GA infants again showed no evidence of improved survival (53 vs. 50%) or improved outcome at 18 months (major handicap rate 32%; vs. 34%). Survival rates improved for 26- to 28-week GA infants, but the survival rate and incidence of major impairment had not improved for of 23- to 25-week GA infants.